Design method of pulse compression linear limiter on basis of Field Programmable Gate Array (FPGA)

Abstract

The invention relates to a design method of a pulse compression linear limiter on the basis of a Field Programmable Gate Array (FPGA). The design method includes that for signals I and signals Q obtained after digital pulse compression, the phase alpha and the module value A of the signals are obtained through real-time calculating in a Coordinated Rotation Digital Computing (CORDIC) method; new signals cos alpha and sin alpha are generated according to the phase alpha through a CORDIC algorithm, an amplitude limiting function is obtained through a lookup table according to the module value A so as to obtain the amplitude limited module value A'; the A' is multiplied with cos alpha and sin alpha to obtain amplitude limited signals I' and amplitude limited signals Q'; the phase of the original pulse compression signals is reserved in the amplitude limited signals I' and amplitude limited signals Q', but the signal dynamic range is compressed. The pulse compression linear limiter on the basis of the FPGA can compress the pulse compression dynamic range of a radar system on the premise of keeping the phase of the original pulse compression signals, leads the dynamic range to be matched with improved factors in moving target processing, enhances the clutter inhibitory effect and plays an important role in engineering application.

Description

technical field [0001] The invention belongs to the field of radar signal processing, and realizes the purpose of compressing the pulse-compressed signal dynamic range by designing an FPGA-based linear limiter. Background technique [0002] In the modern radar system design, the design of the limiter after pulse compression is of great significance. The signal-to-noise ratio of the radar echo signal will be greatly improved after pulse compression, that is, matched filtering, and the dynamic range of the signal will also be greatly improved accordingly. Affected by the working mode of the radar and the clutter environment, the improvement factor of moving target processing is often limited to a certain extent, and the signal dynamic range after pulse compression exceeds the maximum improvement factor of the system, which will cause clutter residue after moving target processing. Based on the above reasons, it is usually necessary to limit the amplitude of the compressed pul...

AI Technical Summary

Problems solved by technology

The limiting method used in the past is to quadrature the pulse pressure I, Q The signals are limited separately, which will destroy the phase of the clutter and affect the subsequent moving target processing

Images